a. Field of the Invention
The present invention relates to ovens for heating food products, and more particularly to an oven in which a variety of food products can be selectively cooked in different time cycles.
b. Background Art
In U.S. Pat. No. 4,491,065, entitled "FOOD HEATING APPARATUS", with the inventor being the same as in the present patent application, there is disclosed a hot air oven which is particularly adapted to cook a food product such as potato pieces in a form which are commonly known as "French fries". An earlier and still more common method of cooking French fries is to deep fry the potatoes (i.e. cut the potatoes into elongate pieces and place these in a wire basket which is lowered into a high temperature cooking oil to cook the potatoes with a crisp fried surface). However, there are a number of drawbacks to that deep fry method of cooking potatoes, such as fire hazards, disposing of the fumes created from the cooking oil, dangers in handling the hot oil, etc. Another consideration is that with increasing emphasis on low fat diets, deep frying in oil is for some people undesirable.
Accordingly, the cooking apparatus of U.S. Pat. No. 4,491,065 provided a hot air oven which alleviated many of the of the problems associated with deep fat frying of potatoes. In this oven, there is provided a heating chamber in which there is positioned a food carrying perforate basket which is rotatably mounted about a longitudinal center axis. In this particular configuration, the basket is formed in two half sections which fit against one another along a central plane coincident with the longitudinal axis of rotation. One half section of the basket is removably mounted to the other section so that it can be slid outwardly to an open position to accept a quantity of potato pieces which are to be cooked, and then slid back into engagement with the other basket section to form a unitary basket structure, after which the basket can be rotated to impart a tumbling action to the potato pieces within the basket.
The oven door is closed, and a fan is operated to circulate air from within the oven chamber through heating coils and thence back into the oven so that the heated air blows through the tumbling potato pieces to cook the same. At the completion of a cooking cycle, the oven door is opened, and the removeable basket section is withdrawn from the oven and emptied so that another batch of potato pieces to be cooked can be placed in the basket half section.
The oven of U.S. Pat. No. 4,491,065 also has control system where there is an on and off switch 150 which energizes the entire system, and also a convection switch 152 which powers the motor that operates the fan to circulate the hot air through the oven. The control system also comprises a timer switch 154 which is rotated to the desired position to time the operation of the oven. A thermostat switch is connected in series with the heating elements to maintain these at the proper temperature. An interlock switch 164 is provided, with this switch 164 becoming conductive by closing the oven door 22. This interlock switch 164 is connected in the series with the aforementioned convection switch 152 and the timer switch 154 so that when the oven door is closed power is delivered to operate the motor 82 which causes rotation of the basket and also to deliver power to the motor 190 to turn the fan which circulates the air through the oven. Thus, when the oven door is opened, air is not circulated through the oven, and the basket does not rotate. There are other specific features of the control system described in U.S. Pat. No. 4,491,065.
Another feature of the oven shown in U.S. Pat. No. 4,491,065 is a circulating system by which expansion air and gaseous substances inside the oven chamber are drawn through a gap like opening above the oven door along with outside air into an upper condensing chamber to condense a high percentage of the condensable material. The remaining gaseous mixture is then discharged by means of a fan to an outside location. Also, there is provided another fan, powered by a motor, to cool the motors and other components located in the oven at a location spaced laterally from the cooking chamber of the oven.
While the apparatus described in U.S. Pat. No. 4,491,065 certainly comprises an oven which serves a very useful function in the cooking art, and while the oven showed in U.S. Pat. No. 4,491,065 can certainly be used with food products other than potato pieces, the inventor in the present patent application recognizes that there are certain cooking applications of a varied nature to which the cooking oven of U.S. Pat. No. 4,491,065 is not readily adapted.
A search of the U.S. patent literature has disclosed a number of other cooking devices of various sorts, some of which provide a plurality of baskets removably mounted to a rotating member. These also have limitations relative to more varied cooking requirements in a restaurant environment. These are the following:
U.S. Pat. No. 4,765,232 (Reid) shows a rotisserie type cooking device where a plurality of food containing baskets is removably mounted by means of clips to a rotating shaft, with these baskets extending radially outwardly from the shaft. A heat source, such as charcoal briquets is placed in the lower part of the housing beneath the rotating baskets.
U.S. Pat. No. 4,723,482 (Weiss et al) shows a sausage heating machine where there is a frame mounted for rotation about a horizontal axis, and there is a plurality of basket members to hold the sausages. Patentability is predicated upon the particular configuration of the basket members which permit the sausage to roll in the basket as the frame is rotated.
U.S. Pat. No. 4,421,016 (Sich) also shows a cooking apparatus where there is a plurality of baskets or food containers which are mounted for rotation about a horizontally extending shaft. Various embodiments are shown. In a first embodiment, there are three such shafts with four baskets on each shaft, with these baskets having a fixed orientation relative to the related shaft. In the embodiment of FIG. 4, each of the individual baskets, in addition to being mounted for rotation about a center shaft, is itself mounted for rotation about a center axis of its own.
U.S. Pat. No. 4,132,216 (Guibert) shows a hot air oven by which a number of prepackaged meals can be heated to a serving temperature. Food trays containing refrigerated food are stacked in a number of sets which are in turn supported from a rotating support frame. These are rotated about a vertical axis, and hot air is circulated through the oven. There is an access port at one side of the oven through which the trays can be inserted into and taken from the oven.
U.S. Pat. No. 3,951,052 (Ringo) shows a barbecuing apparatus where there is a horizontally mounted rotating shaft with a frame to which a plurality of food carrying trays are releasably mounted. As the shaft rotates, these food carrying trays are in turn rotated in a circular path in the cooking chamber. The charcoal fire is located below the food trays, and water is directed at the fire through a plurality of quenching nozzles to control the fire. To retain the baskets in the cooking position, the frame supports the trays and spring arms grip the tray and keep the baskets closed.
U.S. Pat. No. 3,870,193 (Schneider) discloses an automatic vending machine for heated French-fried potatoes in which the French fries are contained in an open ended cage. The cage itself is mounted for rotation about its center axis, and the cage can be tilted about an axis transverse to its axis of rotation so that it can be oriented to receive a load of potatoes, then rotated to a horizontal position for rotation of the cage while heated air is blown through the cage to heat the potatoes, and then moved to a discharge position. A timer is provided to control the length of time of rotation.
U.S. Pat. No. 3,744,402 (Piegza et al) discloses a pressure vessel for uniformly treating articles, such as food products which are sealed in containers, such as glass bottles or metal cans, where the food must be subjected to controlled cooking and/or sterilizing temperatures. The product is contained in baskets which are in turn mounted to a rotatable shaft.
U.S. Pat. No. 3,025,783 (Koudek) shows a rotisserie cooker where there is a rotatable shaft having a square cross-sectional configuration that extends across the cooking area. Individual sleeves 14 are attached to the shaft at spaced locations along the length of the shaft, and individual food containing baskets can be removably mounted to clips 16 connected to each of the sleeves 14. Thus, individual baskets can be selectively mounted to, and removed from, the shaft so that the time period during which the food in the baskets is cooked can be controlled. The arrangement of this apparatus is such that the baskets are necessarily positioned at spaced locations along the shaft, and each basket is properly positioned for removal from the shaft only when it is rotated around to a more forward position.